Steam generator



March 22 ,1927. 1,621,505

O. H. HARTMANN ETAL STEAM GENERATOR Filed March 23, 1925 2 Sheets-Sheet1 ATTORNEYS March 22, 1927. 1,621,505

0. H. HARTMANN ET A1,.

STEAM GENERATOR Filed'March 23,-1925 2 Sheets-Sheet 2 AZ W ATTORNEYSPatented Mar. 22, 1 927.

. UNITED STATES PATENTYOFFICE.

OTTO H. H AR'IMANN-AND ALFRED HERMANUZ, F CAESEL-WILHELHSEOHE, GER-MANY, ASSIGNORS TO SGHMIDTSCHE HEISSDAMPF-GESELLSCHAFT I. B. H., 01'

.CASSEL-WILHELMSHOHE, GERMANY.

STEAM GENERATOR.

Application riled March 23, 1925, Serial 1T0. 17,609,and in GernianyMarch 26, 1924.

Our invention relates to generators of steam and particularly to watertube boilers in which the steam is generated partly by direct heating ordirectly and partly by in- 5 direct heating or indirectly, that is tosay,

by means of a heating medium or a heat carrier circulating in a closedcircuit. According to our invention the heat-receiving portion of thetube system for the heating medium is arranged in the furnace so thatparts of the boiler, such as the brickwork, or the steamand water drum,are protected against excessive heat bythe said portion of the tubesystem forming a protective screen for these parts.

The arrangement of a steam generator according to our present inventionis of special importance in connection with boilers working atvery hightemperatures, for example,

those fired with pulverized coal which have recently been largelyemployed in steam' power installations. A further advantage consists inthe fact that the heating surface of the boiler can be increased byproviding additional surfaces in those parts of the furnacehitherto'unutilized. If the tube system for the heating medium, with theobject of forming several independent circuits, consists of a numberofindividual elements, it is of special advantage to construct eachelement so that that part of it lying outside the water-space of theboiler can be readily detached from the remaining part.

In the accompanying drawings Fig. 1 is a longitudinal section throughthe upper part of a water-tube boiler,.

Fig. 2 being a cross-section on the line 22 of Fig. 1,

Fig. 3 a longitudinal section on the line 3-3 of Fig. 1, and

Fig. 4 a cross-section Fig. 5 shows a second form of the invention.

According to the form shown in Figs. 1 to 4,- the upper steam-and-waterdrum, a, of the boiler has expanded thereinto the usual water-tubes, b.In the water space of this on the line of drum, a, a series of tubeelements, a, are

arranged which are connected by unions, e, or other suitable means withtubes, d, lying between adjacent longitudinal series of water-tubes, b,in the neighbourhood of the points of attachment of these tubes to thedrum, the arrangement being such that each of the tubes, 0, d, forms acircuit closed in itself, while in addition each tube, d, can bedetached. from the corresponding tube, a, and withdrawn from between thewatertubes,.b. Each of the tubes 0, d, contains a heat-carrier, forexample, water or the like which is heated in the parts, d, by the hotgases rising from the furnace or by the radiant heat of the latter, thewater or the like so heated rising to the upper tube, 0, and theregiving up its heat to the surrounding water. In this manner the directheating of the drum, 0, by the hot ases, is assisted in an eflicientmanner by t e indirect heating due to the heat-carrier. The lower length70 of each tube, 0, possesses sufiicient fall to ensure flow ofcondensed heat-carrier to the lower tubes, (Z. The tubes, (1, are soarranged that they more or less fill'the spaces between adjacentlongitudinal series of water-tubes, 6, thereby protecting the lower partof the drum, a, into which the upperends of the water-tubes areexpanded, against the direct action of the hot gases or the radiant heatof the furnace.

In the illustrative form of the invention described, the protective wallfor the drum, a, is formed by the lengths of tube, d, extending only ina longitudinal direction between the water-tubes b.

As an alternative, the heat-receiving part of the tube system containingthe heat-carrier can also be arranged in some other position' in thefurnace, for example, on a wall thereof. Such an arrangement is shown in90 Fig. 5, in which the heat-receiving surface, d, of the heat-carrieris arranged not only below the upper drum, a, but. also in juxtapositionto that surface of the brickwork, f, disposed towards the furnace. 95

The arrangement and structure of the elements, a, d, is the same asabove described with reference to Figs. 1 to 4. v

The forms of the invention illustrated are applicable to stationarywater-tubebozlers. The invention, however, is not restricted to suchanapplication but can be applied with be made without departing from thespirit of our invention as defined in the appended claims.

What we claim is:

L In a steam generator, means including a steam and water container anda plurality of water tubes connected therewith; for generating part ofthe steam directly, a tube system for generating the other part of thesteam indirectly, the heat-receiving portion of said tube system beinglocated as a protective screen in front of parts of said containerxposedto extreme heat.

2. In a steam generator, a furnace a steamand-water container having awall thereof facing said furnace, water-tubes communieating with saidcontainer and being connected with it on the side facing said fur'-nace,-a tube system containing a heating medium for indirectlygenerating part of the steam, a portion of said tube system beinglocated inside said container, another portion of it being locatedoutside the conajplurality of water tubes connected therewith forgenerating part of thesteam directly, a tube system containing a heatingmedium for transferring the heat of the furnace lndirectly to the waterof the container, said tube system consisting of tubes forming a closedcircuit for the heating medium and a protective screen for parts of thecontainer exposed to extreme heat.

4. A steam generator as claimed in claim 3, in which the tube system forthe heating medium consists of a number of individual elements, eachbeing a circuit closed in itself.

5. A steam generator as claimed in claim 3, in whichthe tube system forthe heating medium consists of a number of individual elements, theparts of these elements lying outside the water container being detach-vtective screen for the wall of said container- Where the ends of thewater-tubes are expanded into said wall.

7. A steam generator as set forth in claim 3 in which the tube systemfor the heating medium consists of a number of individual elements, eachforming a closed circuit, in itself and having a detachable connectionbetween the part arranged inside and the part arranged outside of saidcontainer.

8. A steam generator as set forth in claim 2 in which the tube systemfor the heating medium cons sts of a number of individual elements, eachforming a closed circuit in itself and having a detachable connectionbetween that part of each element arranged in said container and thepart arranged outside thereof, said detachable connections being locatedoutside of the furnace walls.

OTTO H. HARTMANN. ALFRED HERMANUZ.

